Vessel occluder

ABSTRACT

A vessel occluder used to occlude blood flow within the vasculature is described. The vessel occluder can include an expandable mesh portion having a flexible membrane that expands within a cavity of the expandable mesh portion. When expanded, the flexible membrane blocks blood passage through the mesh portion.

RELATED APPLICATIONS

This application is a continuation of and claims priority to U.S. patentapplication Ser. No. 15/619,296 filed Jun. 9, 2017 entitled VesselOccluder, which claims benefit of and priority to U.S. ProvisionalApplication Ser. No. 62/348,729 filed Jun. 10, 2016 entitled VesselOccluder, both of which are hereby incorporated herein by reference intheir entireties.

BACKGROUND OF THE INVENTION

Vessel occlusion may be desirable for a number of reasons. Circumstancesinclude treatment of aneurysms, left atrial appendage, atrial septaldefect, fistulas, patent foramen ovale, patent ductus arteriosus, vesselshutdown, or various occlusive purposes in the neuro-vasculature andperipheral vasculature.

Embolic coils are often used for occlusive purposes. The coils fill thetarget treatment site, but may require a substantial amount of time toocclude the treatment area. Vessel plugs conform to the malformation,vessel, or target treatment area and can provide a rapid occlusiveeffect. Vessel plugs are often used where rapid occlusion is desired,since the vessel plug can quickly fill and conform to the target space.Vessel plugs, in order to be effective, typically should be easilydeployable, promote rapid occlusion, and resist migration afterdeployment. However, conventional vessel plugs rarely excel at all ofthese factors.

SUMMARY OF THE INVENTION

The present invention is generally directed to a vascular plug.

In one embodiment, the vascular plug comprises a braided mesh portionthat expands from a generally linear configuration to athree-dimensional shape. For example, the mesh portion can expand to agenerally spherical shape, a concave shape, a flattened oval shape, or aplurality of connected bulbs.

The vascular plug may include a flexible membrane deployed within aninterior of the mesh portion when expanded. For example, the flexiblemembrane can comprise a circular, flat membrane arranged substantiallyperpendicular to a linear axis of the vascular plug. In another example,the flexible membrane expands to a position that is non-perpendicular tothe axis of the vascular plug.

In one embodiment, the flexible membrane is composed of PET, ePTFE, or athin metallic film.

In one embodiment, the vascular plug and its attached pusher areconfigured to delivery microcoils or other embolic material within themesh portion or outside of the mesh portion.

In one embodiment, the vascular plug includes an elastic member withinthe mesh portion to assist in expansion of the vascular plug within apatient.

The present invention is also directed to a method of deploying avascular plug within a patient.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other aspects, features and advantages of which embodiments ofthe invention are capable of will be apparent and elucidated from thefollowing description of embodiments of the present invention, referencebeing made to the accompanying drawings, in which:

FIG. 1 illustrates a vascular plug according to the present invention.

FIG. 2 illustrates a vascular plug according to the present invention.

FIG. 3 illustrates a vascular plug according to the present invention.

FIG. 4 illustrates a vascular plug according to the present invention.

FIG. 5 illustrates a pusher and detachment mechanism.

FIG. 6 illustrates a pusher and detachment mechanism.

FIG. 7 illustrates a pusher and detachment mechanism.

FIG. 8 illustrates a power supply and control system for the detachmentmechanism.

FIG. 9 illustrates another embodiment of a vascular plug.

FIG. 10 illustrates an embodiment of a flexible membrane.

FIG. 11 illustrates an embodiment of a flexible membrane.

FIG. 12 illustrates a flexible plug with an elastic member within it.

FIG. 13 illustrates a flexible plug with an elastic member within it.

FIG. 14 illustrates another embodiment of a vascular plug.

FIG. 15 illustrates another embodiment of a vascular plug.

FIG. 16 illustrates another embodiment of a vascular plug.

FIG. 17 illustrates another embodiment of a vascular plug.

FIG. 18 illustrates another embodiment of a vascular plug.

FIG. 19 illustrates embodiments of a vascular plug with microcoils.

FIG. 20 illustrates embodiments of a vascular plug with microcoils.

FIG. 21 illustrates another embodiment of a vascular plug.

FIG. 22 illustrates another embodiment of a vascular plug withmicrocoils.

DESCRIPTION OF EMBODIMENTS

Specific embodiments of the invention will now be described withreference to the accompanying drawings. This invention may, however, beembodied in many different forms and should not be construed as limitedto the embodiments set forth herein; rather, these embodiments areprovided so that this disclosure will be thorough and complete, and willfully convey the scope of the invention to those skilled in the art. Theterminology used in the detailed description of the embodimentsillustrated in the accompanying drawings is not intended to be limitingof the invention. In the drawings, like numbers refer to like elements.

Vascular plugs are used for various occlusive purposes in thevasculature. These plugs generally conform to the shape of the bloodvessel or blood vessel abnormality thereby occluding and preventingblood flow through or to the target area. Plugs can be used to treat avariety of conditions including aneurysms, left atrial appendage, atrialseptal defect, fistulas, patent foramen ovale, patent ductus arteriosus,vessel shutdown, or can be used for various occlusive purposes in theneuro-vasculature and peripheral vasculature.

Plugs generally provide faster occlusion than other occlusive devicessuch as embolic coils since, rather than filling the target space, theplugs conform to the shape of the target space promoting fasterocclusion. Vascular plugs generally are larger than other occlusivedevices (such as embolic coils) since they are meant to conform to thetarget space, rather than fill the target space. This larger profile canmake deliverability an issue as compared to other occlusive devices,therefore, vascular plugs need to balance the need for rapid occlusionwith the need for ease of deliverability in order to effectively deliverthe plug to the target treatment site.

FIGS. 1-8 illustrate various aspects of a vascular plug 100 that isconnected to a distal end of a pusher 112, allowing the plug 100 to beadvanced through a catheter 113 to a desired target location in apatient. When a mesh portion 102 of the vascular plug 100 is expanded, aflexible membrane 104 is also expanded within the mesh portion 102 tocreate a blockage or barrier at the target location.

The mesh portion 102 expands from an elongated, compressed, cylindricalshape (e.g., when located within the catheter 113) to a longitudinallyshorter and generally spherical expanded shape. The wires of the meshportion 102 can be formed from nitinol, cobalt-chromium, stainless steelwires, or combinations therein. In one example, the mesh portion 102 iscomprised of 48-144 nitinol wires with a diameter range of about0.0008″-0.005″. Optionally, one or more radiopaque wires can be used tocreate the mesh portion 102, to further enhance visualization of thevascular plug 100 during a procedure.

The distal end of the mesh portion 102 terminates with a distal capmember 108 and the proximal end of the mesh portion 102 terminates witha proximal cap member 110. These cap members 108 and 110 can be formedby welding the wires of the mesh portion together, welding the wires todiscrete metal caps, crimping metal cap members onto the wires, or usingan adhesive to attach discrete caps to the wires. Preferably, these capmembers 108 and 110 can be composed of radiopaque materials such thatthey can be used as visual markers during a procedure.

The flexible membrane 104 is described as a membrane, but can be anymaterial that can be unfolded, straightened, stretched, or otherwiseexpanded to an enlarged and preferably planar area. The flexiblemembrane 104 can be composed of a variety of flexible materials that arebiocompatible and preferably that increase a thrombogenic response inthe patient. For example, polyethylene terephthalate (PET) or expandedpolytetrafluoroethylene (ePTFE) can be used. In another specificexample, a composite of PET and ePTFE can be used. In another example,the flexible membrane 104 can be composed of a thin-metallic film, suchas those created via sputtering or vacuum deposition.

The flexible membrane 104 is supported by support frame 106, locatedwithin the cavity of the mesh portion 102. The support frame 106includes a circular ring portion 106C that expands to a diameter that issimilar in size to the largest inner diameter region of the expandedmesh portion 102 and is oriented such that the plane of the ring portion106C is generally perpendicular to an axis between the proximal anddistal end of the mesh portion (e.g., an axis between the caps 108 and110). This orientation allows the flexible membrane 104 to be expandedalmost completely across the cavity of the mesh portion 102 and blockpassage of fluid from a patient between the proximal and distal ends ofthe vascular plug 100.

The flexible membrane 104 can be fixed to the ring portion 106C bycreating a laminating layer over the flexible membrane 104, around thewire of the ring portion 106C, and back upon itself. For example, theflexible membrane 104 can be initially created with PET and a layer ofePTFE can be disposed or laminated over the PET layer and the ringportion 106C. Alternately, the flexible membrane 104 can be stitched tothe ring portion 106C with metal wires or polymer fibers. In anotheralternate embodiment, adhesives can be used for attachment purposes. Inyet another alternate embodiment, the flexible membrane 104 can bedirectly stitched or adhered to the wires of the mesh portion 102.

The ring portion 106C is preferably supported by a distal support arm106A and a proximal support arm 106B. The distal support arm 106A isconnected at its distal end to the distal cap member 108 and extendsaxially, curving radially outward near a center of the mesh portion 102,and ultimately connecting to the ring portion 106C. Similarly, theproximal support arm 106B is connected at its proximal end to theproximal cap member 108 and extends axially, curving radially outwardnear a center of the mesh portion 102, and ultimately connecting to thering portion 106C. The distal support arm 106A may connect to the ringportion 106C at a diametrically opposite location to the connectionpoint of the proximal support arm 106B. In other embodiments, multiplesupport arms can be connected in a similar manner to the ring portion106C. For example, 2, 3, 4, or 5 can be included on both the proximaland distal sides of the ring portion 106C.

As seen in FIGS. 5-8 , the vascular plug 100 can be detached from thepusher 112 via a heater coil 114 on the distal end of the pusher 112that breaks a tether filament 116. Specifically, the tether filament 116is connected to the pusher 112 (e.g., to a structural coil 122), passesthrough the interior of the heater coil 114, through a passage in theproximal end cap 110, and into the mesh portion 102. The distal end ofthe tether filament 116 can be tied into a knot 116A and/or can be fixedwithin the vascular plug 100 via adhesives. When the heater isactivated, the tether filament 116 breaks, releasing the vascular plug100 from the pusher 112.

The heater coil 114 is fixed at a distal end of the pusher 112 to adistal end of a core wire 124 that extends to a proximal end of thepusher 112. A first wire 118 is soldered to a distal end of the heatercoil 114 at location 118A, and a second wire 120 is soldered to aproximal end of the heater coil 114 at location 120A, allowing power tobe selectively supplied and thereby generate heat.

The wires 118, 120 extend proximally within the outer tubular layers126, 128 to the proximal end of the pusher 112; best seen in FIG. 7 .The first wire 118 is fixed to a distal electrical contact 130 and thesecond wire 120 is connected to the core wires 124, which is ultimatelyconnected to a middle electrical contact 130B. These contacts arefurther electrically isolated (e.g., with insulating spacers 132) toprevent an inadvertent short circuit. Hence, an electrically activecircuit can be created by applying power to the distal electricalcontact 130A and middle electrical contact 130B.

Power can be supplied to the contacts 130A and 130B by inserting theproximal end of the pusher 112 into passage 134A of a power control andsupply unit 134. Preferably, the unit includes a button 134B or similaruser interface control to activate the power at a desired time.Optionally, the pusher 112 may include a proximal contact 130C that canbe used by the unit 134 to determine if the pusher 112 has been properlyseated in passage 134A. Similar detachment systems and/or variations canbe found in U.S. Pat. No. 8,182,506, US20060200192, US20100268204,US20110301686, US20150289879, US20151073772, and US20150173773, all ofwhich are incorporated by reference and can be used with this embodiment(as well as any others in this application).

In operation, the catheter 113, with the pusher 112 inside of it, isadvanced within a vessel or lumen of a patient until the distal end ofthe catheter 112 is adjacent the target occlusion site. For example, thedistal end of the catheter 113 may be positioned within or at the mouthof an aneurysm. Either prior to advancement or prior to insertion withinthe patient, the proximal end of the pusher 112, including theelectrical contacts 130A, 130B, and 130C, are inserted into passage 134Aof the supply unit 134.

Next, the pusher 112 is distally advanced (or optionally the catheter113 is retracted) such that the vascular plug 100 is exposed at a distalend of the catheter 113 and located at the desired occlusion site (e.g.,within an aneurysm or within a blood vessel). As the vascular plug 100is exposed, the mesh portion 102 and the flexible membrane 104 expand,substantially blocking flow of bodily fluid (e.g., blood) past it.

Finally, the user activates the button 134B to supply power through thepusher 112 and heater coil 114. As the heater coil 114 heats, it breaksthe tether filament 116 that is connected to the vascular plug 100,thereby releasing the vascular plug 100 from the pusher 112. Finally,the pusher 112 can be withdrawn back into the catheter 113 and bothdevices can be withdrawn from the patient.

Alternately, the vascular plug 112 can be used in a temporary manner.Specifically, the vascular plug 100 can be deployed and then laterwithdrawn back into the catheter 113.

FIG. 9 illustrates another embodiment of a vascular plug 150 that isgenerally similar to the previously described plug 100, but includes aring portion 106C that positions the plane of the flexible membrane 104at a non-perpendicular angle relative to the axis of the plug 150 andpusher 112. In one example, the plane of the ring portion 106C is angledat about 45 degrees relative to the axis of the pusher 112.

While the flexible membrane 104 forms a generally circular shape invascular plug 100, other shapes are possible. For example, FIG. 10illustrates a flexible membrane 152 having a generally “plus” shape witha plurality of radial arm portions 152. In another example, FIG. 11illustrates a flexible membrane assembly 154 comprising a plurality ofgenerally circular support rings 156 that each support discrete flexiblemembranes 158. The rings/membranes may partially overlap with each otherand different numbers of rings/membranes may be used (e.g., 2, 3, 4, 5,or 6). Alternately, each support ring 156 may have a shape other than acircle, such as a square, triangular, wedge-shape, or oval.

Any of the embodiments of a vascular plug described in thisspecification can further include an elastic member 162 within the meshportion 102 to assist in radial expansion. For example, FIG. 12illustrates a vascular plug 160 (which may or may not have a flexiblemembrane 104) that has an elastic member 162 connected to the distal capmember 108 and proximal cap member 110. The vascular plug 160 isdepicted in its compressed configuration (i.e., within the catheter113), such that the elastic member 162 is stretched. In FIG. 13 , thevascular plug 160 is released from the catheter 113, allowing theelastic member 162 to pull the cap members 108, 110 closer to eachother, thereby expanding the mesh portion. The elastic member 162 can beany material that can provide elastic force, such as a spring or astretchable, resilient polymer.

Any of the mesh portions 102 described in this specification can furtherinclude strands of other material 172 woven into the mesh, such as PETfibers, hydrogel fibers, or PET-coated hydrogel fibers, as seen in thevascular plug 170 of FIG. 14 . In one specific example, the mesh portion102 is composed of 144 braided nitinol wires (8 wires are of 0.0025″diameter and 138 wires are of 0.001″ diameter), with 20 PET threadsadhered to a 0.004 inch stainless-steel wire that is sewn in anover-under pattern through the braided nitinol wires.

It should be understood that the mesh portion 102 of any of theembodiments described in this specification can have expanded shapesother than the generally spherical shape of the vascular plug 100. Forexample, FIGS. 15 and 16 illustrates a cross sectional side view and atop perspective view, respectively, of a vascular plug 180 that expandsto a “cup” or distally-facing concave shape. The support ring 106C andflexible membrane 104 are depicted as being within the interior of themesh portion 102, but could alternately be positioned outside of themesh portion 102, in the depression forming the distally-facing concavearea.

In another example shown in FIG. 17 , the mesh portion 102 of a vascularplug 190 can expand to a relatively flat or flattened oval shape. In yetanother example shown in FIG. 18 , a vascular plug 200 may expand to aplurality of axially-aligned bulb shapes 202 (e.g., 2, 3, 4, 5, 6),preferably heat-shaped as such from a single, continuous mesh portion102. A flexible membrane 104 can be fixed within any of the bulbs 202,all of the bulbs 202, or any combination of the bulbs 202.

Any of the embodiments disclosed in this specification can be furtheradapted to also deploy embolic microcoils 212 (or other embolicmaterial, such a liquid embolic material or PET fibers) at variouslocations. For example, FIG. 19 illustrates an embodiment of a vascularplug 210 that is generally similar to previously described plug 100.However, the pusher 112 and proximal end cap 110 may include a passagewithin it that microcoils 212 can be pushed through into the proximalinterior of the mesh portion 102 (the pusher 112 may be a catheter). Theadded microcoils 212 may further enhance blockage.

In another example seen in FIG. 20 , a vascular plug 220 can includes apassage 222 between the proximal cap member 110 to the distal cap member108, allowing the microcoils 212 to be pushed to a distal side of theplug 220. In this example, the mesh portion 102 forms a distally facingconcave shape, in which the microcoils 212 are positioned.

In another example seen in FIG. 21 , a vascular plug 230 lacks aflexible membrane 104, allowing the microcoil 212 to be pushed into theentire interior space of the mesh portion 102.

The microcoil 212 may have a three-dimensional secondary shape impartedto it, allowing it form curves, coils, and similar shapes whenunconstrained. These secondary shapes are generally helpful for creatinga frame around a treatment site, where smaller coils can subsequently beused to fill the treatment site. Other embodiments may utilizenon-complex shaped embolic coils. In one example, the microcoil 212 hasa primary wind diameter (this is the elongated shape of the coil whenits constrained within a delivery catheter) that has a maximum value ofabout 0.023 inches, which allows use within a catheter (or a pusher 112with a microcoil passage) of up to about 0.027 inches internal diameter.The secondary (delivered) wind size range may be between about 2 mm toabout 20 mm. Optionally, the microcoil 212 may be coated or otherwiseimpregnated with hydrogel, and specifically pH-reactive hydrogel thatexpands upon contact with fluids with a particular pH (e.g., pH ofblood).

FIG. 22 illustrates another embodiment of a vascular plug 240, having aplurality of curved structural wires 244 extending between the proximalcap member 108 and the distal cap member 110. A flexible membrane 242 isconnected over or beneath the structural wires 244 and can be composedof a thin-metallic film, such as those created via sputtering or vacuumdeposition. Alternately, the flexible membrane 242 can be composed ofmesh or a polymer, such as PET. Optionally, the vascular plug 244 isconfigured to deliver microcoils 212 within the interior of the flexiblemembrane.

Although the invention has been described in terms of particularembodiments and applications, one of ordinary skill in the art, in lightof this teaching, can generate additional embodiments and modificationswithout departing from the spirit of or exceeding the scope of theclaimed invention. Accordingly, it is to be understood that the drawingsand descriptions herein are proffered by way of example to facilitatecomprehension of the invention and should not be construed to limit thescope thereof.

What is claimed is:
 1. A vascular plug comprising: a mesh portion havinga radially compressed configuration when constrained in a catheter and aradially expanded configuration when unconstrained, wherein the meshportion comprises a proximal end and a distal end; a proximal supportarm spanning a proximal section of an interior of the mesh portion andforming at least a portion of a ring portion in the interior of the meshportion, wherein the proximal support arm extends from the proximal endof the mesh portion to the ring portion; and a membrane fixed to thering portion, the membrane adopting a radially expanded configuration asthe mesh portion adopts its radially expanded configuration, therebylimiting blood passage through the mesh portion.
 2. The vascular plug ofclaim 1, further comprising a distal support arm spanning a distalsection of the interior of the mesh portion.
 3. The vascular plug ofclaim 2, wherein the distal support arm is connected to the distal endof the mesh portion.
 4. The vascular plug of claim 2, wherein theproximal and distal support arms form the ring portion.
 5. The vascularplug of claim 2, wherein the proximal support arm and the distal supportarm curve radially outwardly near a center of the mesh portion to definethe ring portion.
 6. The vascular plug of claim 1, wherein the membraneexpands to an orientation that is perpendicular to an axis between theproximal end and the distal end of the mesh portion.
 7. The vascularplug of claim 1, wherein the membrane expands within the interior of themesh portion at a non-perpendicular angle relative to an axis of anelongated pusher.
 8. The vascular plug of claim 1, wherein the proximalsupport arm is connected between the proximal end and the distal end ofthe mesh portion.
 9. The vascular plug of claim 1, wherein the proximalend and the distal end of the mesh portion are each closed.
 10. Avascular plug comprising: a mesh portion having a radially compressedconfiguration when constrained in a catheter and a radially expandedconfiguration when unconstrained; a distal support arm spanning a distalsection of an interior of the mesh portion and forming at least aportion of a ring portion in the interior of the mesh portion, whereinat least a portion of the distal support arm extends along a centrallongitudinal axis of the mesh portion; and a membrane fixed to the ringportion, the membrane adopting a radially expanded configuration as themesh portion adopts its radially expanded configuration, therebylimiting blood passage through the mesh portion.
 11. The vascular plugof claim 10, further comprising a proximal support arm spanning aproximal section of the interior of the mesh portion.
 12. The vascularplug of claim 11, wherein the proximal support arm and the distalsupport arm curve radially outwardly near a center of the mesh portionto define the ring portion.
 13. The vascular plug of claim 10, furthercomprising a laminating layer disposed over the membrane.
 14. Thevascular plug of claim 13, wherein the laminating layer comprises ePTFE.15. A vascular plug system comprising: an elongated pusher extendingalong a first longitudinal axis; a mesh portion fixed to a distal end ofthe elongated pusher; the mesh portion having a radially compressedconfiguration when constrained in a catheter and a radially expandedconfiguration when unconstrained; a ring portion in an interior of themesh, where the ring portion extends along an axis transverse to thefirst longitudinal axis when the mesh portion is in its radiallyexpanded configuration; a distal support arm or a proximal support armspanning a section of an interior of the mesh portion and forming atleast a portion of the ring portion, wherein at least a portion of thedistal support arm or the proximal support arm extends along a centrallongitudinal axis of the mesh portion; and a membrane fixed to the ringportion, the membrane adopting a radially expanded configuration as themesh portion adopts its radially expanded configuration, therebylimiting blood passage through the mesh portion, wherein the membranespans across the ring portion in a planar orientation.
 16. The vascularplug of claim 15, wherein the membrane expands to an orientation that isperpendicular to the first longitudinal axis.
 17. The vascular plug ofclaim 15, wherein the membrane expands to an orientation that isnon-perpendicular relative to the first longitudinal axis.
 18. Thevascular plug of claim 15, wherein the ring portion extends along anaxis that is perpendicular to the first longitudinal axis when the meshportion is in its radially expanded configuration.
 19. The vascular plugof claim 15, wherein the ring portion extends along an axis that isnon-perpendicular to the first longitudinal axis when the mesh portionis in its radially expanded configuration.
 20. The vascular plug ofclaim 15, further comprising the proximal support arm spanning aproximal section of the interior of the mesh portion and the distalsupport arm spanning the distal section of the interior of the meshportion; the proximal and distal support arms forming the ring portion.